Now, a big part of President Obama's two national campaign victories was a promise to help working families. His critics complain that all these years later, he's still talking about some of the very same policy prescriptions with little to show for it. Today, ideas like paid sick and maternity leave and universal preschool will take center stage at the White House Summit on Working Families, so will the challenges faced by workers caring for their children and sometimes their parents. NPR White House correspondent Tamara Keith introduces us to a couple of the working parents planning to attend.

TAMARA KEITH, BYLINE: Charlotte Brock checks the time on the microwave above her stove.

KEITH: Her 3-and-half-year-old son Gabriel is asleep in the other room.

C. BROCK: Lunches. Three, four, five.

KEITH: This is the only time Brock can find to exercise, and for her, this brief workout is both a key to staying sane and a reminder of the years she spent in the Marine Corps.

C. BROCK: And what I do in between exercises, when I'm recovering, is laundry.

KEITH: Brock is a single mom, and she works full-time for a defense contractor in suburban Virginia.

C. BROCK: Gabriel. Hey, it's morning time.

KEITH: Gabriel is groggy with a big mop of dark hair.

C. BROCK: Can we brush your hair a little bit?

GABRIEL BROCK: No.

KEITH: For Brock and so many people, the work life balance is a constant struggle.

C. BROCK: All kids want their moms to be super mom. I mean, he wants to spend more time with me, asks me why - why can't we be - why can't I stay with you? I want to stay with you. So I try to have really good weekends.

KEITH: Brock's employer at the time Gabriel was born didn't offer paid maternity leave, and child care for infants is wildly expensive. So she quit that job and moved in with her parents for a couple of years. These challenges are not new, and in many ways, they're universal. Now, though, the Obama administration is making an economic argument. Betsey Stevenson is a member of the White House Council of Economic Advisers.

BETSEY STEVENSON: And it's time we start thinking about this as a national problem that's affecting our economy and not our personal problem - like if somehow, I just set the alarm earlier that, you know, I would solve this problem for me, and everything would be fine.

KEITH: The challenges are even more acute for low-income families. That describes Ashley Johnson, who works at a dollar store.

KEITH: Johnson lives with her husband and three young kids in transitional housing provided by Catholic charities. They get free child care. But a couple of months ago, her 2-year-old was really sick.

JOHNSON: She just did not feel good at all. And my husband, he works nights, so he was still at work. So when I got up, you know, I was like there is no way. I can't just send her to day care like that. I can't. I have to call out.

KEITH: Johnson ended up missing two days of work - unpaid. And she says her boss punished her.

JOHNSON: He ended up cutting my hours for the next week. So I only get 25 hours, so he ended up cutting my hours down to 10.

KEITH: Paid sick leave - something President Obama supported as a senator and as a candidate. But even a Democratic-controlled Congress early in his presidency failed to act. Now he has even less influence over Congress. Alabama Republican Congresswoman Martha Roby has two kids and a work-family juggle of her own. Last year, the House passed her Working Families Flexibility Act. But Democrats panned it.

CONGRESSMAN MARTHA ROBY: I think we absolutely need to be having a discussion about what can we do to ease burdens on working families as it relates to the federal government. The difference is, I don't believe the federal government should be mandating to businesses how to do it.

KEITH: President Obama may disagree with that sentiment, but from a practical perspective, it's what he is left with. So this morning, he'll sign an executive order to allow federal workers greater access to flexible work arrangements. And he'll call for Congress to protect pregnant women from workplace discrimination. Instead of the sweeping overhaul Democrats once hoped for, Obama is holding a summit and encouraging businesses and states to change workplace policies on their own. Tamara Keith, NPR News.